Death Roll (Ex)

When grappling a foe of its size or smaller, a addanc can perform a death roll upon making a successful grapple check. As it clings to its foe, it tucks in its legs and rolls rapidly, twisting and wrenching its victim. The addanc inflicts its bite damage and knocks the creature prone. If successful, the addanc maintains its grapple.

Hold Breath (Ex)

An addanc may hold its breath for (four times its Con score) rounds before beginning to drown.

Swimming Grapple (Ex)

The addanc is a solitary predator that builds dams to
create small lakes. Once its territory is defined, anything that comes
near to the lake or adjoining river becomes the addanc’s prey. The beast
hunts by floating just under the surface of the water and waiting for
its next meal to approach, at which point it attacks with a
bone-crunching bite. With the prey held tight in its jaws, the addanc
attempts to drag its quarry under the water. Both industrious and
conniving, this monster possesses enough intelligence to wait for its
prey to be the most vulnerable. Once it attacks, it goes immediately for
the kill, giving its prey little chance to resistance. It cares not for
its prey; it cares only for itself.

Like the natural beaver’s lodge, an addanc’s lair can
only be accessed from below the water’s surface. The structure is a
truly grisly location. As the creature uses the possessions and remains
of its victims for decoration, and the stench of decay permeates the
entire lair. The adjoining damn is composed of heavy tree branches and
logs while long bones of larger prey are interspersed to shore the
structure. A typical addanc lair is between thirty and fifty feet in
diameter and rises about fifteen feet above the surface of the water.